Mobile Health and Varenicline: A New Frontier in HIV Tobacco Cessation

Can Mobile Health and Pharmacotherapy Transform Tobacco Cessation in HIV?

A groundbreaking clinical trial is underway in India to address the critical issue of tobacco cessation among people with HIV (PWH), combining mobile health technology with pharmacotherapy in a novel approach that could significantly impact treatment strategies in resource-limited settings. This hybrid implementation-effectiveness study, currently recruiting participants, represents an important step forward in addressing the disproportionately high tobacco use among PWH in low- and middle-income countries (LMICs), where prevalence is 1.3 to 1.4 times higher than in the general population. The research addresses a crucial health gap, as PWH who adhere to antiretroviral therapy but continue smoking face approximately ten times greater risk of dying from lung cancer than from AIDS itself, along with elevated risks for cardiovascular and chronic lung diseases.

The study is being conducted at the Chennai Antiviral Research and Treatment Clinical Research Site (CART CRS) at the Voluntary Health Services Infectious Disease Medical Center (VHS IDMC), which serves over 5,000 HIV patients in Chennai. With India home to more than two million PWH and an estimated 267 million adult tobacco users, the country presents a particularly significant setting for this research. The Indian tobacco landscape is uniquely complex, featuring a wide array of both smoked products (cigarettes, bidis, hookah) and smokeless variants (khaini, pan masala, betel quid), with multiple product use common among PWH. Despite the availability of cessation resources including medications and a free national Quitline with multi-language support, utilization of these services remains low, with only 4.1% of smokers using cessation pharmacotherapies and just 9.0% accessing counseling services when attempting to quit. Financial barriers may contribute to this gap, as a course of nicotine replacement therapy in India costs between INR 730-1,535 (approximately USD $28-44), while varenicline can cost up to INR 10,016 (about USD $114) for a 12-week course.

What Innovative Strategies Drive This Trial’s Design?

The trial employs a rigorous type 1 hybrid implementation-effectiveness design, randomizing eligible adult HIV patients who smoke tobacco to either an integrated intervention or standard care in a 1:1 ratio. The integrated intervention combines Positively Smoke Free Mobile (PSF-M), a culturally adapted mobile health behavioral intervention, with varenicline pharmacotherapy. PSF-M was specifically modified for the Indian context using the Cultural Accommodation Model of Substance Abuse Treatment (CAMSAT), a four-stage process that involved gathering information from multiple sources, accommodating practices to fit local needs, pilot testing with focus groups in relevant languages (English, Tamil, and Telugu), and implementation. The final version includes 704 messages delivered over 42 days via WhatsApp, featuring text, images, and links to eight educational videos. The behavioral content is complemented by varenicline, prescribed using a standard escalating dose regimen starting with 0.5mg once daily for 1-3 days, followed by 0.5mg twice daily for 4-7 days, and then 1.0mg twice daily for 11 weeks.

The control arm receives standard care consisting of brief advice based on the Ask, Advice, Refer model and connection to the national Quitline. This approach aligns with the Framework Convention on Tobacco Control, to which India is a signatory, and utilizes existing healthcare infrastructure. The Quitline service includes four counseling sessions: pre-quit date, post-quit date, and two follow-up support calls. To ensure methodological rigor, randomization is stratified by gender, language preference, and tobacco use patterns, with treatment assignments concealed through a REDCap database. Participants lacking access to mobile devices are provided with low-cost smartphones, removing potential technological barriers to participation. The primary outcome measure is biochemically validated 7-day point prevalence abstinence (PPA) from all tobacco products at 24 weeks after treatment initiation, verified using urine cotinine testing. Secondary outcomes include self-reported prolonged abstinence at 12 and 24 weeks, point prevalence abstinence at multiple timepoints, and number of quit attempts.

How Do Analysis and Economic Evaluations Inform Clinical Practice?

The study's statistical approach includes both intention-to-treat analysis (where missing outcomes are classified as continued tobacco use) and complete case analysis. With a targeted enrollment of 400 participants (200 per arm), the trial is powered to detect a relative risk of 2.24 for the primary outcome, based on abstinence estimates of 8-10% in the standard care arm from previous studies among PWH. The investigators will also conduct moderator analyses to identify potential subgroups with differential treatment effects and mediator analyses to understand how the intervention achieves its effects, focusing on changes in cessation self-efficacy and nicotine dependence. Implementation outcomes will be assessed using Proctor's framework, collecting data on adoption, feasibility, acceptability, appropriateness, fidelity, usability, and cost through surveys, fidelity checklists, user engagement metrics, and qualitative interviews with staff. This mixed-methods approach will provide valuable insights into the practical aspects of implementing the intervention in real-world clinical settings.

The research team will conduct 12-20 qualitative interviews with staff in various roles (physicians, counselors, clinic leadership) to understand adaptation processes, barriers and facilitators to adoption, and requirements for sustainability in the IDMC practice. These interviews will be conducted in English and/or Tamil, audio recorded and professionally transcribed for thematic analysis. The study is adequately powered to detect small to medium effect sizes for implementation outcomes, with 80% power to detect a standardized effect size of 0.28 and 90% power to detect an effect size of 0.33 for continuous outcomes, as well as at least 80% power to detect a 15% difference between study arms for dichotomized outcomes.

Cost-effectiveness analysis will utilize the Simulation of Tobacco and Nicotine Outcomes and Policy (STOP) microsimulation model, which tracks individuals' transitions between tobacco use states based on initiation, cessation, and relapse rates. This sophisticated modeling approach will project long-term impacts on life expectancy and healthcare costs, accounting for both sustained abstinence and potential relapse among participants. The model incorporates quality-of-life values for different smoking states and can stratify smokers by intensity of product use, providing a comprehensive economic evaluation of the intervention's value. Data sources for this analysis include surveys conducted among trial participants about healthcare utilization and quality of life (using the EQ-5D instrument), as well as staff surveys about time spent delivering the intervention. Healthcare service costs and staff time valuations will be derived from published literature and local economic data.

How is Patient Safety Monitored and Future Impact Envisioned?

Ethical oversight is maintained through review and approval by both the Dana-Farber Cancer Institute (DFCI: 22-356) and the VHS Ethics Committee (VHS-IEC/97-2022), with a dedicated Data Safety Monitoring Board meeting biannually to review trial procedures and safety data. All participants provide written informed consent, and HIV treatment adherence remains a priority throughout the trial, though current ARV adherence or viral suppression are not inclusion criteria since tobacco cessation is expected to benefit PWH regardless of their HIV treatment status. Adverse events and serious adverse events are assessed at 1, 2, and 4 weeks post-enrollment by telephone and at in-person study visits at 12 and 24 weeks, with serious adverse events followed until resolution.

While the study design does not allow for testing the independent effects of PSF-M and varenicline separately, the primary focus is on determining whether the integrated treatment model outperforms standard care in a clinically relevant comparison. The researchers acknowledge that findings from Chennai may not be directly generalizable to all LMIC settings, but the comprehensive assessment of implementation processes and cost-effectiveness should provide valuable insights into the potential for broader dissemination. By generating evidence on both effectiveness and implementation in a resource-limited setting, this trial addresses a critical gap in tobacco cessation research among PWH and could significantly influence treatment strategies in similar contexts globally. Could this integrated approach combining digital behavioral support with pharmacotherapy become a model for addressing tobacco cessation in HIV care settings across LMICs? How might the cultural adaptation process used in this study inform the development of other behavioral interventions for diverse populations? What systemic changes would be needed to implement such an approach at scale if proven effective?

Summary

A hybrid implementation-effectiveness clinical trial currently underway in Chennai, India, is investigating an innovative approach to tobacco cessation among people living with HIV (PWH) by combining mobile health technology with varenicline pharmacotherapy. The study addresses a critical health gap in low- and middle-income countries where tobacco use among PWH is significantly elevated, and PWH who smoke face approximately ten times greater risk of dying from lung cancer than from AIDS itself. The trial randomizes 400 participants to either an integrated intervention consisting of Positively Smoke Free Mobile (PSF-M)—a culturally adapted WhatsApp-based behavioral program delivering 704 messages over 42 days—plus varenicline, or standard care including brief advice and national Quitline referral. The research employs rigorous methodological approaches including biochemically validated abstinence measures, implementation outcome assessments using Proctor's framework, qualitative staff interviews, and cost-effectiveness analysis using microsimulation modeling. Conducted at a facility serving over 5,000 HIV patients in a country with more than two million PWH and 267 million adult tobacco users, the study utilizes the Cultural Accommodation Model of Substance Abuse Treatment to adapt interventions for the complex Indian tobacco landscape that includes both smoked and smokeless products. With comprehensive evaluation of effectiveness, implementation processes, and economic impact, this trial could provide crucial evidence to inform tobacco cessation strategies for PWH in resource-limited settings globally, potentially establishing a scalable model for integrating digital behavioral support with pharmacotherapy in HIV care.